Do all of your brothers and sisters look exactly like your parents and each other? Seeds are embryonic plants, produced by the combination of genetic material from the parent plants. Plants have sperm which must penetrate the egg for fertilization to take place. Those sex cells contain lots of genetic information and it can be difficult to control how that information is expressed.

Pollen, by the way, is the container for the sperm cells and you understand how pollen gets transferred far and wide. That's called sexual propagation.

Roses, fruit trees, woody plant cultivars are all cloned. That's called vegetative or asexual propagation. In most cases, it's the only way to produce identical plants.